/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_SEM_QUEUE_H
#define FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_SEM_QUEUE_H

#include <condition_variable>
#include <mutex>
#include <queue>

namespace Keels::Ace {
template<class T>
class SemQueue {
public:
    void PopFront(T& t)
    {
        std::unique_lock lock(mutex_);
        if (queue_.empty()) {
            const auto& func = [this]() { return !queue_.empty(); };
            cv_.wait(lock, func);
        }
        t = queue_.front();
        queue_.pop();
    }

    void Push(const T& t)
    {
        std::unique_lock lock(mutex_);
        queue_.push(std::move(t));
        cv_.notify_all();
    }

private:
    std::queue<T> queue_;
    std::mutex mutex_;
    std::condition_variable cv_;
};

} // namespace Keels::Ace
#endif // FOUNDATION_ACE_FRAMEWORKS_BASE_THREAD_SEM_QUEUE_H
